The flags of Romania have combined the major colors of the arms and flags of Moldavia and Wallachia since 1859. The arms formulated in 1872 were used until 1921. The change in arms reflected the Union of 1 December 1918 which transferred new areas that were formerly part of the Austro-Hungarian Empire to Romania. Necessarily, such a change modified all flags that used the arms. The major changes were the addition of the arms of the House of Hohenzollern, the Crown of Romania and the dolphins which represent the Black
Sea.

I hope that Mario Fabretto will not mind, but I took his flag of the king of Romania and modified it to develop three new royal flags: the queen's standard, the crown prince's standard, and the standard of other princes.Calvin Paige Herring, 30 April 1998

Queen's standard:

by Calvin Paige Herring from rendering by Mario Fabretto

Crown prince's standard:

by Calvin Paige Herring from rendering by Mario Fabretto

Other prince's standard:

by Calvin Paige Herring from rendering by Mario Fabretto

Queen Mother's Standard:

by
by Calvin Paige Herring

This flag was somewhat unique in that it appears to have had a pink background.Calvin Paige Herring, 3 January 1999

I didn't find the "queen mother standard" in my exemplar of Flaggenbuch. It is the source?.

I believe that a range of royals standards were adopted 24-APR-1922, and previosely the royal standard was a square national flag with full arms and a crown in each corner (without crowns for the heir prince). Before 1921 no standard for the queen or queen mother is reported in my sources.Jaume Ollé, 6 January 1999

In the additional pages for the Flaggenbuch (1939), it is there.Calvin Paige Herring, 06 January 1999